Having recently been awakened to the variety of triplets that can be achieved on uilleann pipes, there's one example I've noticed on the new Tiarnan O'Duinnchinn album that is kind of hard to wrap my head around:

The grace notes are tight to the point of being percussive, almost like a typewriter was hammering out the triplet. It sounds qualitatively different from other triplets, and I thought maybe he was tapping or sliding over the A note hole, briefly stopping the entire chanter as in the notorious back D thumb triplet, but believe I've ruled that possibility out. Still, the A note sounds sustained, i.e. it doesn't seem he is stopping all holes to prepare for a regular closed style triplet, but is playing the triplet over an open A, as if it were a cran on A. My best guess is that its an impeccable BCB(C) cran- or open-style triplet played over an open A (with that final cut on C).

Also, in the same vein and from the same album, there are some more tricky triplets here, in this case played on B: